IE84107B1 - Improvements in the manufacture of hurling balls or like balls. - Google Patents

Description

IMPROVEIVIENTS IN THE MANUFACTURE OF HURLING BALLS OR LIKE BALLS The present invention relates to balls and the manufacture of balls, in particular balls that are used for playing hurling.

Hurling is one of the four native Gaelic sports and is recognised by many to be the most skillful of all. Players use hurling sticks to strike a ball commonly referred to as a sliotar.

Traditionally the sliotar is a small hard ball with a diameter ranging between 23cm and 25cm. The ball is formed by initially winding a length of yarn around a cork core until a sphere with a minimum diameter of approximately 21cm is achieved. The sphere is then dipped in a water repellant substance such as wax prior to being covered. Once suitably covered, the ball is finished and ready for use.

Generally the cover is comprised of two pieces of leather, each piece being cut into a figure eight shape. When in the same plane, the two pieces are orientated such that their longitudinal axes are mutually perpendicular. The wider part of one piece is then stitched to the narrow part of the second piece and vice versa to enclose and cover the clipped sphere. It is important for hurling balls to be solid throughout as a solid ball has a slower bounce than a hollow ball and this is a desirable characteristic for the game of hurling.

A disadvantage of the known hurling balls is that the balls are not a consistent size and do not behave in use in a consistent manner since the technique employed to make the balls varies considerably between different manufactures. In an effort to maintain standards, the Gaelic Athletic Association (GAA) has specifications to which the manufactured hurling ball must comply. There is therefore a need to provide a new method of manufacturing a ball with consistent dimensions and characteristics, which adhere to the regulatory bodies’ requirements.

It is an object of the present invention to seek to alleviate the above mentioned problems.

Accordingly, the present invention provides a method of making a hurling ball comprising manufacturing a core element for the ball by forming a solid sphere by; filling a spherical mould with a mixture of a polymerisable material and a polymerisation initiator and/or catalyst selected to yield a core element having a density range of between 400 kg/m3 and 500 kg/ m3; optionally providing heat or light to the mixture in the mould; allowing the mixture to polymerise and solidify during a period of curing to form a solid spherical core element in which the core element has the density range between 400 kg/m3 and 500 kg/m3; extracting the resulting solid spherical core element from the spherical mould; and covering the core element with a covering material.

Preferably the core element has a density of about 450 kg/m3.

Preferably, the polymerised core element is resiliently deformable. ldeally, the solid spherical core element is formed when a polymerisable material is placed within a suitably shaped mould, cured, allowed to set and then extracted from the mould. In a preferred arrangement, the mould comprises two hollow hemispherical components, which are joined together and secured forming an enclosed spherical mould of defined dimensions. The mould is not limited to this arrangement as an enclosed spherical mould can be formed from either a single unit or a plurality of units secured together. Alternatively the mould could comprise two hollow hemispherical components or a plurality of components that remain unattached to each other. Once the polymeric substance has been cured and set within each mould, it can be extracted and the resulting solid pieces can be stuck together using techniques known to those skilled in the art to form the solid spherical core element.

Ideally the closed mould includes at least one sealable aperture through which the uncured polymeric material may be introduced into the mould. The aperture can be situated at any convenient position on the surface of the spherical mould. Ideally, the mixture of polymerisable monomer and initiator or catalyst that is used to form the core element is injected into the spherical mould via the aperture.

It is preferable to form the spherical core element from a polymeric substance that is not brittle or too dense, but rather is shatterproof and sufficiently resiliently deformable to afford the ball the desired bounce characteristics. Suitable materials include polyurethane and polyether, however any suitable material known to those skilled in the art can be used.

For example, a polyester balanced polyurethane supplied by Huntsman is suitable for the manufacture of a hurling ball. Preferably, a catalyst, for example an amine based catalyst, or initiator is added to the uncured polymeric material. Ideally the material within the spherical mould is treated at this stage to polymerise it. For example, if the material used was a polyester balanced polyurethane, the monomer and catalyst are injected into the mould and treated by applying heat, whereupon the monomer and catalyst react to form the polymer. The polymer sets forming a solid sphere within the mould. The solid sphere is removed from the spherical mould by separating the two hemispherical component parts.

The spherical core element of the ball can be formed with any desired dimensions simply by altering the size of the mould. The core element is covered using techniques known to those skilled in the art with any suitable material, although leather is generally preferred for hurling balls. The technique of forming a solid core element is readily adaptable to any like ball, for example cricket balls or hockey balls.

The invention will hereinafter be move particularly described with reference to the accompanying drawings, which illustrate by way of example an embodiment of a ball according to the invention.

Figure 1 is a perspective view of two hemispherical moulds; Figure 2 is a view of a solid spherical core element for a hurling ball; Figure 3 is a plan View of an element of leather covering; and Figure 4 is a view of a finished hurling ball.

Referring initially to Figure 1, there is shown a perspective view of two hemispherical moulds 1 and 101 respectively. The hemispherical moulds 1 and 101 are joined at the edges 11 and closed together by securing means (not shown). In this example, the monomer mixture chosen is one which produces a polyester—balanced polyurethene polymer. Such a mixture is available from Huntsman. The catalyst is an amine. When polymerised the monomer mixture forms a polymeric solid spherical core element with a density of about 450 kg/m3. The mixture of monomer and catalyst is injected into the mould cavity 10 through the aperture 12. The mould is then heated to promote polymerisation of the materials within the mould to form the polymer. Once formed, the mixture fills the entire cavity within the mould and solidifies into a solid sphere.

On cooling, the two hemispherical moulds are released and separated enabling extraction of the solid sphere. Figure 2 is a representation of the formed solid sphere 2, which comprises the spherical core element of the ball. The spherical core element is covered using techniques known in the art to form the ball.

There is a distinctive method employed to cover a hurling ball. Figure 3 shows a piece of leather covering 3 cut in the shape of a figure eight and pierced around the edges with a plurality of holes 31. Two identical such pieces of leather covering 3 are used to cover the spherical core element, the pieces being positioned such that their longitudinal axes are mutually perpendicular in the same plane with the wider part 32 of one piece nestled into the narrower part 33 of the second piece. The pieces are then stitched around the spherical core element through the holes 31 such that the stitched hem projects outwards from the ball.

Figure 4 is a drawing of a finished hurling ball 4 with a solid spherical core element.

Ideally the stitched hem 34 is treated with a water repellant substance to prevent water from damaging the interior of the ball covering.

For the purpose of regulating the production of hurling balls the GAA have specifications to which any manufacturer must comply. The hurling balls manufactured using this technique with polyester balanced polyurethane supplied by Huntsman as the polymeric material have the following specifications, which comply with the GAA’s requirements.

SIZE 5 SIZE 4 Weight of leather cover and thread 25g 23g Sphere in Circumference 21 cm - 22cm 20cm - 21cm Weight of Sphere 85g — 90g 65g — 75g Density of Sphere 400g/L - 500g/L 400g/L — 500g/L It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined by the appended claims.

Claims (10)

CLAIMS:

1. A method of making a hurling ball comprising manufacturing a core element for the ball by forming a solid sphere by; filling a spherical mould with a mixture of a polymerisable material and a polymerisation initiator and/or catalyst selected to yield a core element having a density range of between 400 kg/m3 and 500 kg/ m3; optionally providing heat or light to the mixture in the mould; allowing the mixture to polymerise and solidify during a period of curing to form a solid spherical core element in which the core element has the density range between 400 kg/m3 and 500 kg/m3; extracting the resulting solid spherical core element from the spherical mould; and covering the core element with a covering material.

2. A method according to Claim 1, in which the core element has a density of about 450 kg/m3

3. A method according to Claim 1 or Claim 2, in which the polymerised core element is resiliently deformable.

4. A method according to any of Claims 1 to 3, in which the mould comprises two hollow hemispherical components, which are joined together and secured forming an enclosed spherical mould of defined dimensions.

5. A method according to any preceding claim, in which the closed mould includes at least one sealable aperture through which the uncured polymeric material is introduced into the mould.

6. A method according to any preceding claim, in which the polymerisable material is selected so that the polymerised solidified core is shatterproof and sufficiently resiliently deformable to afford the ball the desired bounce characteristics.

7. A method according to any preceding claim, in which the polymerisable material comprises polyurethane or polyether. 7

8.A method according to Claim 6, in which the polymerisable material comprises a polyester balanced polyurethane.

9. A method according to any one of the preceding claims, in which the covering material comprises leather.

10. A method of making a hurling ball, substantially as herein described with reference to the accompanying drawings. MACLACHLAN & DONALDSON, Applicants’ Agents, 47 Merrion Square,